Exhaust gas conducting sections for exhaust gas turbochargers, which comprise a regulating device for regulating a fluid, generally exhaust gas, flowing through the exhaust gas conducting section, are known. The regulating device is provided for opening and closing a bypass duct in the through-flow exhaust gas conducting section for bypassing a turbine wheel of the exhaust gas conducting section which is rotatably arranged in a wheel chamber of the exhaust gas conducting section. It comprises a cover element for opening and closing a flow cross-section of the bypass duct. By means of such a regulating device, it is possible to bypass the turbine wheel completely or partially in defined operating points of the exhaust gas turbocharger, in particular in operating points, which exhibit large flow quantities, so that an efficient operation of the exhaust gas turbocharger is achieved.
Additionally, it is required to provide a through-flow opening of a double-flow turbine which comprises a first spiral duct and a second spiral duct with a movable cover element which allows both an overflow of exhaust gas from the one spiral duct into the other one and an outflow into the bypass duct.
It is the object of the present invention to provide a regulating device for an exhaust gas turbocharger, which allows a compact construction of the exhaust gas turbocharger.